Mowing attachment



March 14, 1967 c. F. BARBER 3,308,611

MOWING ATTACHMENT Filed Jan. 2Q, 1964 3 Sheets-Sheet l INVENTOR6209.91.55 El /73:1?

ju y 494m ATTORNEYS March 14, 1967 c. F. BARBER MOWING ATTACHMENT 3Sheets-Sheet 2 Filed Jan. 20, 1964 m T. m. V m

ATTORNEYS March 14, 1967 c. F. BARBER MOWING ATTACHMENT 5 Sheets-Sheet 5Filed Jan. 20, 1964 INVENTOR 1 54954-7? United States Patent 3,308,611MOWING ATTACHMENT Charles Frederick Barber, Cambridge, Ohio, assignor toNi) Trim, Inc., Cambridge, Ohio, a corporation of 0 io Filed Jan. 20,1964, Ser. No. 338,998 11 Claims. (Cl. 56-25) This invention relates tomowing attachments of the type carried by a tractor or the like and inparticular to the mounting of such attachments in a manner to reduce thedamaging effects of shocks produced during normal operation and when theattachment strikes an obstruction.

More particularly, the invention relates to improvements in the type ofmowing attachment disclosed in the Stewart Patent No. 2,997,835. Thistype of attachment includes a vertical mast carried at the side of thetractor and mounted thereon for swinging movement about a vertical axis.A cutting head is supported from the mast through a series ofarticulated arms, the innermost of which is pivoted to the mast .in themanner of a boom for swinging movement in a vertical plane. The verticalswinging movement is controlled by means of a hydraulic piston andcylinder. In this type of arrangement considerable wear and tear on thehydraulic system and on the mountings for the mast are experienced whenthe cutting head meets an obstruction during for ward movement of thetractor. Even during normal operation considerable vertical shock forcesand vibration are transmitted to the hydraulic system by the boom.

It is a primary object of the present invention to provide an improvedmast and boom construction for mowing attachments which reduces thedamaging effects of shocks which occur both during normal operation andupon striking of the cutting head against an obstruction.

It is a further object to provide an improved mast construction formowing attachments which permits the mast and the elements supportedthereby to swing rearwardly when the cutting head strikes an obstructionand which then automatically returns the mast to its normal operatingposition.

It is a further object to provide a mast construction for a mowingattachment in which the mast is releasably indexed at its operativeposition, and returned thereto after being displaced, by a spring-biasedmember held in contact with a cam member.

It is a still further object to provide a boom construction for a mowingattachment in which a piston and cylinder for controlling verticalmovement of the boom coacts with the boom through a hoist lever whichpivots independently of the boom and which acts on the boom through aresilient shock absorbing element.

The invention will be further understood from the following detaileddescription of a specific embodiment taken with the drawings in which:

FIGURE 1 is a perspective view of a tractor carrying a mowingattachment;

FIGURE 2 is a fragmentary plan view, partly in section, of the mast ofthe moving attachment of FIGURE 1;

FIGURE 3 is a fragmentary perspective view of the mast of the movingattachment of FIGURE 1;

FIGURE 4 is the same as FIGURE 3 with the mast rotated 90 degrees inwhich position the cutting head would be disposed in front of thetractor; and

FIGURE 5 is a fragmentary elevational view, partly in section, of theboom of the mowing attachment of FIGURE 1.

Referring to FIGURE 1 there is shown a tractor having attached to itsright hand side a mowing attachment 12 which embodies the principles ofthe present invention. The attachment 12 includes as major elements itsforward end to the tractor frame.

3,398,611 Patented Mar. 14, 1967 ice a cutting head such as a sickle barassembly 14, an outer arm 16, a channel shaped inner arm or boom 18 anda channel shaped support stand or mast 20 which is pivotable about avertical axis by means of an arrangement which is one of the features ofthe invention. The sickle bar assembly 14, which may be of any suitableconstruction is swivelly attached to the outer end of the outer arm 16for rotation about the longitudinal axis of the outer arm 16 and aboutan axis 22 at right angles to the plane of the outer arm 16 and the boom18. As shown in FIGURE 1 the sickle bar asembly 14 is disposed at theside of the tractor but it may also be disposed in front of the tractorby rotating the mast degrees. Complete details of the manner in whichthe assembly '14 may be mounted are set forth in the aforementionedPatent No. 2,997,835.

The inner end of the outer arm is provided with a pair of longitudinallyextending ears 24- which are pivoted on the outer end of the boom 18 bymeans of a horizontal pin 26 passing through the ears 24 and through theflanged portions 18a, 18b of the boom 18. The other end of the boom 18terminates between the upper ends of the flange portions 20a, 20b of themast 20 and is pivoted thereto by a horizontal pin 28.

The attachment 12 is controlled and operated hydraulically by a systemwhich includes a rotary hydraulic motor 30 carried by the outer arm 16for operating the cutting mechanism of the sickle bar assembly 14 andthree hydraulic cylinders 32, 34 and 36 for controlling movement of thearticulated members. The cylinder 32 is carried by the outer arm 16 forrotating the sickle bar assembly 14 about the axis 22 through a sprocketand chain linkage (not shown). The cylinder 34 is disposed between andpivoted at 38 to the flange portions 18a, 18b of the boom 18. Itsextensible piston arm 40 is pivoted by means of a pin 42 to the upperend of a short link 44 whose lower end is pivoted on a pin 46 carried bya pair of depending ears 4 7 on the boom 18. Another link 48 extendsoutwardly from the pin 42 to a pin 49 carried by the cars 24 on theouter arm 16.

The cylinder 36 is inclined upwardly and outwardly from a horizontalpivot pin 50 carried by the lower ends of the flange portions 20a, 20bof the mast 20. The extensible piston arm 52 of the cylinder 36 isconnected to the central portion of a relatively short channel shapedhoist lever 54 by means of a horizontal pin 56 extending between theflange portions of the lever 54. The inner end of the lever 54 ispivoted on the pin 28 independently of the boom 13. Its outer end, whichis offset downwardly from its inner end, cooperates with the adjacentportion of the boom 18 through a compression spring assembly 57 whichwith the lever 54 constitutes another feature of the invention.

The hydraulic system for operating the motor 30 and the cylinders 32, 34and 36 also inclues a hydraulic pump (not shown) carried by the tractor1i flexible hydraulic conduits (not shown) and control valves (notshown) which are controlled by the tractor operator in a manner known inthe art.

As indicated above, one of the features of the invention is the mannerin which the support stand or mast 20 is mounted for permitting themower assembly 12, when carried at the side of the tractor, to breakaway or swing rearwardly when the sickle bar assembly 14- meets anobstruction. As seen in FIGURE 1, the supporting framework for the mast20 includes an elongated vertical plate 58, the upper end of which isbraced by means of a horizontal member 60 extending across the top oftractor 10 at a location above the rear of the engine hood and aforwardly and downwardly extending strut 62 secured at The end of thehorizontal brace 60 opposite the support plate 58 is secured to avertical side brace 64 which is reinforced by another inclined strut 66.As best seen in FIGURE the upper end of the mast is closed with ahorizontal plate 68 which is pivoted to the end of the horizontalsupport member 60 by means of a vertical sleeve 70 passing through themember 60 and the plate 68. The sleeve 70 is retained in place by meansof a ring 72 which is clamped against the upper end of the sleeve 7 0 bymeans of bolts 74 threaded into the upper surface of the member 60. Itwill be appreciated that other means may be provided for pivotallymounting the upper end of the mast 20; the sleeve arrangement is aconvenient construction because it provides a passageway and retainerfor the hydraulic lines (not shown) leading to the cylinders 32, 34 and36 and the motor 30.

As best seen in FIGURE 3 the lower end of the vertical support plate 58is secured, as by welding to an outwardly extending horizontal cam plate76 which is mounted on top of a horizontal channel member 78 by means ofscrews 80, the heads of which are countersunk in the upper surface ofthe plate 76. The inner end of the channel member 78 is secured to thetractor frame 79 by suitable brackets illustrated at 81 and 82. Avertical pivot pin 84 lying on the axis of the sleeve 70 extendsupwardly through the web portion of the channel 78, through the camplate 76 and through a horizontal foot plate 86 which is welded betweenthe lower ends of the flange portions 20a, 20b of the mast 20. A washer(not shown) is disposed around the pin 84 between the foot plate 86 andthe cam plate 76 to provide bearing surfaces.

According to the principles of the invention the fixed cam plate 76together with a movable cam engaging member such as a latch lever 88 andassociated elements provide for the break-away feature referred toabove. Referring particularly to FIGURES 3 and 4 it will be seen thatthe lever 88 depends from a horizontal pivot pin 90 which is mounted inthe flange portions 20a, 20b of the mast 20 a short distance above theouter edge of the cam plate 76. The lower portion of the lever 88extends through a guide slot 92 in the foot plate 86 and is engageablewith the outer and forward edges of the cam plate 76. As best seen inFIGURE 2 the outer edge of the cam plate 76 has a generally V-shapednotch 94 into which the lever 88 is biased by a pair of spiral tensionsprings 96 disposed between the flange portions 20a, 20b of the mast 20.The springs 96 are hooked at their inner ends to a bracket 98 which iswelded to the web portion of the mast 20' and at their outer ends to abracket 100 which is welded to the lever 88. The mast 20' will thus berestrained by engagement of the lever 88 with the notch 94 againstrotation about the vertical axis through the bolt 84 and the sleeve 70.However, when the sickle bar assembly 14 meets an obstruction duringforward movement of the tractor torque will be applied to the mast todisplace the lever 88 and allow the mast to rotate clockwise as viewedin FIGURE 2.

The portion of the outer edge of the cam plate 76 which is rearward ofthe notch 94, extends outwardly as well as rearwardly and forms a camsurface 104 on which the lever 88 rides when the mast is rotated duringa break-away operation. After the lever 88 has been displaced from thenotch 94 continued rotation of the mast slides the lever 88 rearwardlyalong the edge 104 and simultaneously moves its lower portion outwardly.This action continually increases the tension in the springs 96 so thatcontinually greater restraint against rotation of the mast 20 iseffected. The are through which the mast may rotate is limited by anupstanding stop member 105 welded to the latch plate 76 in a position toengage flange 20a at about 27 of rotation from the operative position.More important, however, is the effect of the outward angling of theedge 104 which assures that the force applied by the lever 88 to theedge 164 will tend to return the mast to its original position when thetorque which produced its deflection is removed.

From FIGURE 2 it will be apparent that, by virtue of the relationship ofthe pivot bolt 84, the points of attachment of the springs 96 and theangle of the edge 104, the resultant force of the springs 96 on the mast20 will tend to rotate it counterclockwise from positions in which thelever 88 engages the edge 104 of the cam plate 76. If the mast 20 shouldovershoot the notch 94 when it is being returned to its operativeposition the springs 96 will produce an opposite torque by virtue of theengagement of the lever 88 with a flat edge portion 106 of the plate 76which extends forwardly of the notch 94. Stated in different words, itwill be seen that the attachment of the springs 96 is such that theyexert a pull substantially along a line passing through the axis ofrotation of the mast 26 so that the force of the lever 88 on anystraight edge such as the edges 104 and 186 produces a torque on themast except when the straight edge is at a right angle to a line passingthrough the axis of rotation. While the arrangement of the parts in theillustrated embodiment is a preferred construction it will be apparentthat the principles involved do not limit the arrangement to the onedisclosed.

The forward edge of the cam plate 76 has generally V-sha-ped groove 108which is disposed at a right angle to the groove 94. When it is desiredto mow grass adjacent the front of the tractor 10, the mast 20 isrotated counterclockwise from the FIGURE 2 position until the lever 88slips into the groove 108, as illustrated in FIG- URE 4. Then the sicklebar assembly 14 is rotated about the longitudinal axis of the arm 16 soas to be in a position to engage grass and the like upon forwardmovement of the tractor. Once the lever 88 has been displaced from thegroove 94 and has negotiated the straight edge 106 very little force isnecessary to continue to rotate the mast 20 because the major portion ofthe edge of the cam plate 76 between the grooves is curved in an arc 116having a radius passing through the axis of rotation of the mast 20. Toretain the mast in a forwardly facing position a removabie stop block112 is disposed adjacent the outer flange 20a of the mast by attachingit to the cam plate 76 with a pair of screws 114 threaded into tappedholes 116. The same block may be used as a stop 118 to prevent forwardrotation of the mast when the latter is in the position shown in FIGURES1, 2 and 3 by attaching it to the cam plate 76 forwardly .of the groove94 with screws 120 threaded into tapped holes 122.

According to another feature of the invention, the mechanism for raisingand lowering the boom 18 includes the hoist lever 54 and the springassembly 57 which is illustrated in detail in FIGURE 5. As shown, theassembly 57 includes a heavy compression spring 124 retained between theend of the hoist lever 54 and the boom 18 by means of two tubularmembers 126 and 128 which are secured as by welding to the boom 18 andto the hoist lever 54, respectively. The spring 124 resides primarilywithin the member 126, but normally projects from the lower end thereofa suflicient distance to support the boom 18 in spaced relation to thehoist lever 54. The upper end of the tubular member 126 is closed by anexteriorly threaded plug 136 which abuts the upper end of the spring 124and which may be employed to adjust the compression of the latter. Abolt 132 extends through the plug to aid in aligning the spring 124 andis secured to the plug 139 as by welding so that the latter may berotated with a wrench. As described before, the hoist lever 54 and theboom 18 are independently rotatable on the pin 28 so that the boom 18may move against the action of the spring 124 even though the hoistlever is being held stationary by the hydraulic cylinder 36.

While not shown in the drawings it will be understood that the pivotpins for the various articulated members will be protected fromexcessive wear by suitable bushings and lubrication passages.

In using the mowing attachment 12 it is usually desired to dispose thesickle bar assembly 14 laterally to the side of the tractor 10, as shownin FIGURE 1. In this position the channel-shaped mast 20 faces outwardlyand is releasably restrained against rearward rotation by .angagement ofthe latch lever 88 in the notch 94 of the cam plate 76. Forward rotationof the mast 20 is positively restrained by engagement of the mast 20with the stop 118. The tractor operator then drives the tractorforwardly and manipulates the hydraulic control valves (not shown) toposition the sickle bar assembly 14 for a cutting operation eitherparallel to and close to the ground or in an elevated angular positionfor trimming bushes, hedges and small tree branches. Raising andlowering of the boom 18 is effected by the hydraulic cylinder 36 and thehoist lever 54, but the boom may also move independently of the cylinder36 and lever 54 by virtue of the spring 124. Thus minor vibrations ofthe boom 18 and slight vertical movements thereof are accommodated andabsorbed by the spring 124 and are not transmitted to the hydraulicsystem.

If during forward movement of the tractor 10 the sickle bar assembly 14,the outer arm 16 or the boom 18 meet an obstruction such as a stump,rock, large tree branch or road sign, the resulting torque about thevertical pivot axis of the mast 20 will displace the latch lever 88 fromthe slot 94- in the cam plate 76. The mast 20 together with thearticulated members carried thereby then rotate rearwardly against theaction of the tension springs 96 in the manner already described.Simultaneously the compression spring 124 will absorb at least part ofany vertical shock transmitted to the boom 18. While the direction ofthe shock will be primarily toward the rear of the tractor, the shape ofthe obstruction and the position of the sickle bar assembly 14 may alsotend to move the boom 18 upwardly or downwardly.

When the mowing attachment 12 clears the obstruction either by way ofpassing over it or, in severe cases, by the operators stopping andreversing the tractor 10, the tension springs 96 return the mast 20 toits normal cutting position in the manner already described.

It will be appreciated that the shock absorbing and automatic returnfeatures of the invention effect several advantages of safety andeconomy. The resilient connection between the hydraulic cylinder 36 andthe boom 18 reduces the transmission of normal vibration and normaloscillation of the boom 18 to the hydraulic system and thereby reduceswear and tear on the latter. The same connection together with thebreak-away construction reduce the possibility of damage or breakage .ofthe articulated parts in the event that an obstacle is encounteredduring forward movement of the tractor. The breakaway feature is also asafeguard for the tractor operator who might be injured by the breakingof parts of the attachment or, in severe cases, upsetting of thetractor. The possibility of either of these occurrences is much reducedbecause the operator can stop the tractor or make other adjustments assoon as the break-away feature goes into operation. The automatic returnafter a break-away requires no attention by the operator and therebyplaces the equi ment in position for immediate use as soon as theobstruction is cleared.

While a preferred form of the invention has been described andillustrated modifications thereof will be apparent to those skilled inthe art without departing from the principles of the invention.Therefore it is not intended that the details of the describedembodiment be limiting except as they appear in the appended claims.

What is claimed is:

1. In a mowing attachment for use in combination with a tractor or thelike; a vertical support mast rotatable through an are about a verticalaxis; a boom member pivoted at one end to said mast for rotation in avertical plane; a cutting head supported from the other end of said boommember; a hoist lever disposed below said boom member and pivoted at oneend to said mast; a piston and cylinder device disposed below said hoistlever and pivoted at its ends to said hoist lever and said mast; acompression spring between said hoist lever and said boom member forreducing transmittal of vibration and vertical shock forces from saidboom member to said piston and cylinder device; a cam member having anotch therein and a cam surface adjacent said notch, said cam surfaceextending in a plane which is at right angles to the axis of rotation ofsaid mast; a movable cam engaging member, one of said members beingfixed with respect to said mast and the other being carried by saidmast; a spring urging said cam engaging member into engagement with saidcam member so as to releasably latch said mast against rotation whensaid member resides in said notch, said cam surface having a contourwhich when engaged by said member, converts part of the force of saidtension spring into torque on said mast in a direction to pivot saidmast toward a position in which said member resides in said slot.

2. In a mowing or cutting attachment for use in combination with atractor or the like: a vertical support mast rotatable through an arcabout a vertical axis; a cutting head; means connecting said cuttinghead with said mast for rotation therewith about said vertical axis;means for releasably restraining said mast against pivotal displacementcaused by the engagement of said cutting head with an obstruction duringmovement of the tractor and for restoring said mast to its formerposition after displacement, said means including a cam member having anotch therein and a cam surface adjacent said notch and a cam engagingmember, one of said members being fixed with respect to said mast andthe other carried by said mast and further including means biasing saidcam engaging member into contact with said cam member whereby engagementof said cam engaging member in said notch releasably latches said mastin a predetermined position, said cam surface having a configurationwhich converts at least a portion of the force of said biasing meansinto torque which tends to pivot said mast toward at position in whichsaid cam engaging member resides in said slot.

3. Apparatus as in claim 2 wherein said cam member includes a horizontalplate, an edge of which defines said cam surface, said plate being withrespect to said mast and wherein said cam engaging member is carried bysaid mast.

4. Apparatus as in claim 3 wherein said biasing means includes a tensionspring carried by said mast, said spring exerting pull on said camengaging member along a line generally through said vertical pivotalaxis of said mast.

5. Apparatus as in claim 3 wherein said plate has a second notch thereinat a right angle to said first-mentioned notch whereby said mast may belatched in a second position.

6. In a mowing attachment for use in combination with a tractor or thelike: a cutting head; a boom member carrying said cutting head at oneend; means pivoting the other end of said boom member for rotation in avertical plane; power means cooperating with said boom memberintermediate its ends to support said boom member and to move the sameupwardly and downwardly in said vertical plane, said boom member beingfree to move upwardly with respect to said power means withoutcorresponding movement of the latter; and shock absorbing means forreducing the transmittal of vibration and vertical shock forces fromsaid boom member to said power means over a wide range of positions ofsaid boom member, said shock absorbing means being disposed betweenengaging said power means and said boom member whereby said boom membercan move upwardly relative to said power means when said cutting headstrikes an obstruction without transmitting shock to said power meansand whereby during normal operation vibration and vertical shock forcesto said power means are reduced.

7. Apparatus as in claim 6 wherein said power means includes anextensible piston and cylinder element, a lever rotatable in a verticalplane by said piston and cylinder element, said shock absorbing meansincluding a 7 resilient member disposed between one end of said leverand a downwardly facing surface on said boom member; and pivot meanssupporting the other end of said lever for said rotation.

8. Apparatus as in claim 7 wherein said resilient member is acompression spring.

9. In a mowing attachment for use in combination with a tractor or thelike: a vertical support mast; a boom member pivoted at one end to saidmast for rotation in a vertical plane; a cutting head; means connectingsaid cutting head and the other end of said boom member; a hoist leverdisposed'below said boom member and pivoted at one end to said mast forrotation in a vertical plane; a piston and cylinder device disposedbelow said hoist lever and pivoted at one end to said mast for rotationin a vertical plane, the other end of said piston and cylinder devicebeing pivoted to said hoist lever intermediate the ends thereof; and acompression spring disposed between said hoist lever and said boommember.

References Cited by the Examiner UNITED STATES PATENTS 5/1957 Allen eta1. 5625.4 7/1962 Shelter 56-25.4

ABRAHAM G. STONE, Primary Examiner.

RUSSELL R. KINSEY, Examiner.

1. IN A MOWING ATTACHMENT FOR USE IN COMBINATION WITH A TRACTOR OR THE LIKE; A VERTICAL SUPPORT MAST ROTATABLE THROUGH AN ARC ABOUT A VERTICAL AXIS; A BOOM MEMBER PIVOTED AT ONE END TO SAID MAST FOR ROTATION IN A VERTICAL PLANE; A CUTTING HEAD SUPPORTED FROM THE OTHER END OF SAID BOOM MEMBER; A HOIST LEVER DISPOSED BELOW SAID BOOM MEMBER AND PIVOTED AT ONE END TO SAID MAST; A PISTON AND CYLINDER DEVICE DISPOSED BELOW SAID HOIST LEVER AND PIVOTED AT ITS ENDS TO SAID HOIST LEVER AND SAID MAST; A COMPRESSION SPRING BETWEEN SAID HOIST LEVER AND SAID BOOM MEMBER FOR REDUCING TRANSMITTAL OF VIBRATION AND VERTICAL SHOCK FORCES FROM SAID BOOM MEMBER TO SAID PISTON AND CYLINDER DEVICE; A CAM MEMBER HAVING A NOTCH THEREIN AND A CAM SURFACE ADJACENT SAID NOTCH, SAID CAM SURFACE EXTENDING IN A PLANE WHICH IS AT RIGHT ANGLES TO THE AXIS OF ROTATION OF SAID MAST; A MOVABLE CAM ENGAGING MEMBER, ONE OF SAID MEMBERS BEING FIXED WITH RESPECT TO SAID MAST AND THE OTHER BEING CARRIED BY SAID MAST; A SPRING URGING SAID CAM ENGAGING MEMBER INTO ENGAGEMENT WITH SAID CAM MEMBER SO AS TO RELEASABLY LATCH SAID MAST AGAINST ROTATION WHEN SAID MEMBER RESIDES IN SAID NOTCH, SAID CAM SURFACE HAVING A CONTOUR 